Try to use discriminating terms that are likely to be found only in the documents you seek. The more words you give, the better results you'll get.

The search will find documents containing as many of these words and phrases as possible, ranked so that the documents most relevant to your query are presented first. The search returns relevant results even if they don't contain all query terms.

Identify phrases with quotation marks; for example, "Littoral Surface Craft" or "cruise missiles".